21001122002100 has 72 divisors (see below), whose sum is σ = 60778256817600. Its totient is φ = 5598915745280.

The previous prime is 21001122002093. The next prime is 21001122002129. The reversal of 21001122002100 is 120022110012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7429872 + ... + 9859271.

It is an arithmetic number, because the mean of its divisors is an integer number (844142455800).

Almost surely, 2^{21001122002100} is an apocalyptic number.

21001122002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001122002100 is an abundant number, since it is smaller than the sum of its proper divisors (39777134815500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21001122002100 is a wasteful number, since it uses less digits than its factorization.

21001122002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17293209 (or 17293202 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21001122002100 its reverse (120022110012), we get a palindrome (21121144112112).

The spelling of 21001122002100 in words is "twenty-one trillion, one billion, one hundred twenty-two million, two thousand, one hundred".